Israel strikes Syria after projectile lands in Golan Heights

An Israeli military vehicle drives during training in the Israeli-controlled Golan Heights, near the border with Syria, Tuesday, Sept. 13, 2016. Israel is denying Syrian government claims that its forces shot down a warplane and a drone near the Israeli-controlled part of the Golan Heights. Israeli warplanes have conducted several air raids on Syrian army positions over the past weeks after stray shells hit the Israeli-occupied area. (AP Photo/Ariel Schalit) (The Associated Press)

An Israeli tank drives during training in the Israeli-controlled Golan Heights, near the border with Syria, Tuesday, Sept. 13, 2016. Israel is denying Syrian government claims that its forces shot down a warplane and a drone near the Israeli-controlled part of the Golan Heights. Israeli warplanes have conducted several air raids on Syrian army positions over the past weeks after stray shells hit the Israeli-occupied area. (AP Photo/Ariel Schalit) (The Associated Press)

An Israeli soldier walks past tanks during training in the Israeli-controlled Golan Heights, near the border with Syria, Tuesday, Sept. 13, 2016. Israel is denying Syrian government claims that its forces shot down a warplane and a drone near the Israeli-controlled part of the Golan Heights. Israeli warplanes have conducted several air raids on Syrian army positions over the past weeks after stray shells hit the Israeli-occupied area. (AP Photo/Ariel Schalit) (The Associated Press)

The Israeli military says its aircraft struck artillery positions in Syria after a projectile hit the Israeli-controlled part of the Golan Heights.

Tuesday's incident was the fifth since last week in which fighting in Syria has spilled over into Israel, and the first since a U.S.-Russian brokered truce went into effect to try and end Syria's war, now in its sixth year.

Israel has largely remained on the sidelines of the fighting, but has carried out reprisals on Syrian positions when errant fire has previously landed in Israel.

Israel is also widely believed to have carried out airstrikes on arms shipments said to be destined for the Lebanese militant group Hezbollah, a close ally of the Syrian government.

Israel captured the Golan Heights from Syria in the 1967 Mideast war.